In the advancement of polymer science, an exciting and developing field of microfluidics based on polymer materials is growing. As presented on page 59 by Michael Lee, Maria J. Lopez-Martinez, Abdellatif Baraket, Nadia Zine, Jaume Esteve, Jose A. Plaza, Nicole Jaffrezic-Renault, and Abdelhamid Errachid, the image depicts a negative-structured silicon micromixer fabricated by DRIE for passive mixing. The micromixer is used as the master mold for the production of PDMS replicas by softlithography and bonded to various APTES functionalized thermoplastic films (PI, PET, and PEN) with oxygen plasma treatments. Here, an optical microscope image of a section of mixing loops is exploited by alteration of the optical filters, with a variation of dark and white field illumination for a proposed emphasis of rapid mixing.

The study by F. Collette et al. on page 176 focuses on a new flexible approach for the synthesis of drug delivery submicroparticles functionalized by several molecules (therapeutic agent, fluorescent dye, etc.). Particles are obtained by copolymerization of norbornene with a functionalized-norbornenyl poly(ethylene oxide) macromonomer in dispersion. An accumulation of the drugs carriers in tumor tissues is due to the enhanced permeability and retention effect. Nanoparticles are then internalized in human cells by endocytocis. During this intracellular mechanism, any bioactive molecules found at the surface of the particles, which possesses an acido-sensitive bond, can be released by acidic hydrolysis. Efficient nanoparticle endocytosis has been observed by microscopy in mesothelioma and adenocarcinoma cells using rhodamine B as fluorescent dye.

Post-polymerization modification is a very powerful strategy for the preparation of functional polymers. This Highlight article presents an overview of the evolution of this synthetic strategy, from the first examples that date back to H. Staudinger and earlier into the synthetic toolbox that it represents in contemporary polymer science.

The first example of a living carbocationic polymerization in emulsion is presented. Isobutylene was copolymerized with alloocimene, a tri-terpene. AFM, TEM, and DSC analysis demonstrated a phase separated nanostructure. NMR and TGA revealed the presence of a diblock structure in the material that displayed thermoplastic elastomeric properties with 6 MPa tensile strength and 1000% strain at break. Triblocks were also prepared by sequential monomer addition, yielding 12 MPa tensile strength with 640% strain at break.

Step growth polymerization of an α-azide-ω-alkyne monomer by copper-catalyzed azide-alkyne cycloaddition affords a high molar mass linear poly(1,2,3-triazole) that is subsequently reacted with iodomethane to yield the corresponding poly(3-methyl-1,2,3-triazolium iodide) derivative. The formation of this new type of poly(ionic liquid) having main-chain 1,2,3-triazolium groups in the repeating unit is demonstrated by 1H NMR. The large variety of 1,2,3-triazole-based architectures accessible by anion exchange and macromolecular engineering through click chemistry open new perspectives in the field of poly(ionic liquid)s.

Thermoresponsive and pH-responsive hybrid materials based on the assembly of gold nanorods into multiresponsive, crosslinked copolymer microgel particles were synthesized. These microgel particles were prepared by the surfactant-free emulsion polymerization of N-isopropylacrylamide and acrylic acid with N, N&&num;133;′-methylene bis-acrylamide as a crosslinker. Cetyltrimethyl ammonium bromide-stabilized gold nanorods were also prepared independently using a seed-mediated growth method and then loaded into swollen, deprotonated, acrylic acid-containing microgel particles using the electrostatic interactions between the oppositely charged particles.

In the advancements of polymer science, an exciting and developing field of microfluidics based on polymer materials is growing. These polymers offer attractive and alternative options that are cost effective, flexible, and biocompatible. Microfluidics involves the manipulation of a liquid and one of these components consists of micromixers. By integration with micro-total analysis systems, micromixers can be applied to a whole host of fluidic applications that are beneficial to society.

A new series of side-chain liquid-crystalline dendrimers (LCDs) was successfully synthesized via grafting vinyl-terminated phenyl benzoate-based promesogens to a novel polypropyleneimine (PPI)-derived dendritic polyols. Both of the two LCDs organized in smectic layered phases. Furthermore, the vinyl-terminated LCDs were used to exploit novel elastomers by hydrosilylation crosslinking of vinyl groups. The lamellar structures of original dendrimers were found to reserve in the elastomer networks.

Enantiopure styrene derivatives with chiral secondary hydroxy groups were obtained by enantioselective reduction of the corresponding ketone using alcohol dehydrogenase. The homo and copolymerization of these monomers using reversible addition fragmentation chain transfer yielded enantiopure homo and copolymers. The polymer analogous esterification of the hydroxy groups with an enantioselective lipase was only possible on the (R)-enantiomers in agreement with the enantiomeric preference of the lipase. This selectivity was retained in mixtures of enantiopure polymers.

A new low bandgap polymer PBDTT-ID based on isoindigo and bis(2,3-dialkylthienyl) substituted benzo[1,2-b:4,5-b′]dithiophene has been synthesized. A power conversion efficiency of 4.02%, an Voc of 0.94 V, a FF of 50%, and a Jsc of 8.55 mA cm-2 have been achieved in polymer solar cell devices with the polymer as donor and PC61BM as acceptor under the illumination of air mass (AM) 1.5G, 100 mW cm−2.

The polymerization of 2,2,6,6-tetramethylpiperidin-4-yl methacrylate (TMPM) by atom transfer radical polymerization (ATRP) is studied. The successful polymerization of styrene from PTMPM-Cl macroinitiators by ATRP is then demonstrated, affording PTMPM-b-PS diblock copolymers. Oxidation of the PTMPM-b-PS block copolymer leads to poly(2,2,6,6-tetramethylpipridinyloxy-4-ylmethacrylate)-b-poly(styrene) (PTMA-b-PS). The cyclic voltammogram of PTMA-b-PS indicates a reversible redox reaction at 3.6 V (vs. Li+/Li). Such block copolymers open new opportunities for the formation of new organic cathodic materials.

1,2-Limonene oxide and α-pinene oxide are two high reactivity biorenewable monomers that undergo facile highly exothermic photoinitiated cationic ring-opening polymerizations using both diaryliodonium salt and triarylsufonium salt photoinitiators. The photocopolymerizations of these two biorenewable monomers with several multifunctional epoxides were carried out and it was observed that these monomers were effective in increasing the reaction rates and shortening the induction periods.

New materials and deposition methods are being sought for electrolyte membranes for use in proton exchange membrane fuel cells. Perfluorosulfonic acids associate high conductivity and high chemical stability and much research is dedicated to developing newer generations of short side chain perfluorosulfonic acid (PFSA) of low equivalent weight owing to their advantageously higher glass transition temperature and proton conductivity. In this work, the effects of the side-chain length on the properties of electrospun long- and short-side-chain PFSA are compared.

Polymer-supported polyacrylamide hydrogel membranes were prepared using different initial concentrations of monomer and crosslinker, resulting in permeabilities (km) ranging from 0.199 to 6.343 × 1018 m2. Polymer-coated gold nanoparticles (AuNPs) were filtered through these membranes, showing that the greater the km value, the larger AuNPs passed into the permeate. Equal concentrations of all the different AuNPs were filtered from the smallest to the largest pore-sized membranes, resulting in good size selectivity and a high percentage of AuNPs trapped within the membranes.

Comb polymers composed of a polymethacrylate backbone and poly(2-ethyl-2-oxazoline) side chains exist as macromolecular bottlebrushes in aqueous solution, revealing a transition from ellipsoidal to a cylindrical shape around a backbone degree of polymerization of 30. The polymers exhibit lower critical solution temperature behavior in aqueous solution. The application of various techniques (phase diagram, turbidimetry, dynamic light scattering, small-angle neutron scattering, and transmission electron microscopy) provides access to information of the influence of the polymeric architecture upon its thermoresponsive properties.

The photopolymerization rate enhancement observed when the diacrylamide dental adhesive monomer DEBAAP is copolymerized with a monomer bearing phosphonic acid moieties to improve adhesive strength and durability is explained by an increase of the polarity of the polymerizing medium. Indeed, the effect is small with monomers bearing phosphonate moieties, but is observed when a nonpolymerizable organic phosphonic acid is present in the polymerizing medium.

Nitrile-ligated copper(II) and zinc(II) complexes comprising (fluoroalkoxy)aluminates as weakly coordinating anions have been successfully applied for the synthesis of the highly reactive polyisobutylene. A detailed study of the catalytic system showed that the polymerization reaction is dominated by transfer reactions that lead to the high content of exo double bonds while propagation proceeds via conventional cationic polymerization.

The efficient fluorescence resonance energy transfer (FRET) between amphiphilic dendrimers with oligo(p-phenylenevinylene) core branches and oligo(ethylene oxide) termini have been observed in micelles. The Stern-Volmer constants (KSV) for two donor-acceptor pairs, designated as Den 30 –40 and Den 50 –40, were found to be 4.51 × 10−5 and 8.78 × 10−5 M, respectively. The effects of external stimuli such as solvent and temperature on FRET have been also investigated.

The synthesis of a biocompatible nanocarrier is described using two nonaggressive standardized procedures. In the first, an azido-terminated NB-PEO α-norbornenyl poly(ethylene oxide) macromonomer is functionalized by click chemistry and then polymerized by ROMP in dispersed media using Grubbs' Catalyst as initiator to form functionalized particles. In the second procedure, azide containing particles are synthesized and the functionalization occurs subsequently. This project presents an innovative approach where universal polymeric vectors can be functionalized using any alkyne-modified active molecule.

An efficient synthetic route for synthesis of a series of dicationic ethylene glycol based-ionic liquids with variety of cations, anions, and different chain lengths is described. All prepared ionic liquids were characterized via NMR and ESI-TOF, and exhibit high thermal stability and low glass transition temperatures.

Vinyl esters exhibit low toxicity together with good mechanical properties, which qualifies them to be potential alternatives to state-of-the-art methacrylates. A drawback of a certain class of these vinyl esters containing easily abstractable hydrogens is their moderate reactivity. With the help of thiolene polymerization, the reactivity was enormously improved up to a level of acrylates.

Living anionic and reversible addition–fragmentation chain transfer polymerizations were combined for the preparation of styrene (Sty) and 2-vinyl pyridine (2VPy) or 4-vinyl pyridine (4VPy) amphiphilic diblock copolymers of high molecular weights, in the range between 42,300 and 271,000 g mol−1, and VPy content ranging from 16 to 78 mol %. The self-assembly in the bulk of the synthesized diblock copolymers was investigated using transmission electron microscopy, which revealed the formation of Sty spheres, VPy spheres, or VPy cylinders.

Radical ring-opening polymerization of a five-membered cyclic vinyl sulfone monomer, 2-vinylthiolane-1,1-dioxide (VTDO), proceeded in bulk by use of p-toluenesulfonyl iodide (TosI) or bromide (TosBr) as a radical initiator. When 10 mol % of TosBr was used, the isolated yield of PVTDO reached 49%. The PVTDO synthesized using TosBr had an Mn of 4100 with a relatively narrow, monomodal distribution of molecular weight of 1.8.